THIS INVENTION relates to a ramp assembly arranged for providing access between a vehicle and ground or a platform. In particular but not limited the ramp assembly is arranged for a railway car having a door opening and a floor and is self adjusting for varying heights between the floor and the ground or platform.
The applicant has noted that there is often a considerable high step between the floor of a vehicle and the ground or platform. Passengers must therefore step up when entering the vehicle and step down when leaving the vehicle. Many people have difficulties in stepping into or out of vehicles. In particular the aged, young children, most disabled persons and all people in wheelchairs cannot enter or leave vehicles without assistance from other people.
Certain public transport authorities have movable ramps in an effort to allow wheelchaired persons to use public transport without assistance. These ramps are usually kept at stations where the public transport vehicles stop for picking up new passengers and for dropping passengers at destinations. The applicant has also noted other authorities employ movable elevators instead of ramps.
In use, each of the ramps or elevators is manually moved to a door opening of a vehicle for use by the people in wheelchairs. After use, they are moved back to storage and are often locked for security reason. The relevant authorities employ people to physically move them in position for use by the people in wheelchairs and move them back to storage after use.
Moving the ramps or elevators to positions takes time and it sometimes prevents a vehicle from leaving on time. Using them can therefore disrupt time tables of the public transport. This is undesirable especially during peak hours when there is little opportunity to make up time.
The heights between the floors of vehicles and the ground or platforms vary considerably. It is not aware that any attempt has been made to assist people with difficulties stepping into or out of a vehicle to use the vehicles without assistance.
It is therefore an object of the present invention to alleviate or to at least reduce to a certain level one or more of the above mentioned disadvantages.
In one aspect therefor the present invention resides in a ramp assembly for a vehicle having a door opening and a floor. The assembly comprises a housing member for fixing to the vehicle at or beneath the floor and substantially in line with the door opening, an extendible ramp body controllably positionable between an extended position and a retracted position, and a drive arrangement for controllably driving the ramp body between the extended position and the retracted position. In the extended position the ramp body extends inclinedly from or adjacent to the floor to the ground or platform. In the retracted position the ramp body is positioned within the housing member.
The housing member may be fixed to the vehicle so that it is substantially parallel with, inclined to or perpendicular to the floor.
It is preferred that the ramp body has articulated means along its length so that it can move in a predetermined trajectory path between the retracted position and the extended position.
More preferably, the articulated means includes a pair of spaced beams arranged in the direction of travel of the body and a plurality of slats arranged between the beams.
Desirably, each of the beams has a plurality of links and adjacent links are pivotally joined together for providing said articulation in the ramp body.
The links are conveniently shaped so that adjacent links have a desired angle of articulation and a desired camber in the beams.
Typically, opposing faces of adjacent links have mating linkage parts which are pivotally joined together for providing articulation to said ramp body. The linkage parts may be recessed so that all links are in the same plane. Each of the linkage parts may also have an outer substantially curve-shaped edge surface and an inner substantially curve-shaped edge surface for matingly co-operating with the outer-surface of an adjacent link.
The mating linkage parts can also have co-operating articulation limiting means for limiting the angle of articulation. The articulation limiting means are conveniently shaped articulation limiting edge surfaces on the mating linkage parts so that they are in abuttal relationship when said adjacent links are of a desired maximum angle of articulation.
The positions of the opposing edges remote from the articulation limiting means are shaped to provide cooperating camber angle limiting parts. Typically the camber angle limiting parts are straight surfaces on said portions of the opposing edges and the distance between the surfaces of each link is selectively determined for the desired camber angle.
The drive arrangement may include a controllable reversible or reciprocable drive means for reversibly or reciprocally driving the ramp body between the retractable position and the extended position, a plurality of guide means for guiding the ramp body to move along the trajectory path and an endless drive band which is connected to the ramp body for moving therewith. Preferably the drive means has a support arrangement for supporting the ramp body at said extended position. Where the drive band is a chain, the drive means desirably includes a drive sprocket which is coupled to the drive shaft of a reversible motor drive or a linear to rotary converter driven by a pneumatic or hydraulic ram, a lower control sprocket, an upper control sprocket which is also arranged for supporting the ramp body at the extended position, a plurality of guide sprockets for guiding the chain and a plurality of trajectory control sprockets for determining the trajectory path of the ramp body.
A tensioning sprocket may also be provided for adjusting the tension on the chain.
Where the endless drive band is in the form of a belt the sprockets may be replaced with pulleys.
Where the clearance below the floor is limited the links may be shaped so that the ramp body may be placed in a substantially folded or spiral shape when in said retracted position.
Desirably the endless drive band is arranged so that the assembly is substantially under the vehicle or within allowable space clearance from the vehicle.
Advantageously the drive arrangement incudes a delivery guide to guide the ramp body in an upwardly inclined direction when initially moving out of the housing for extending to the extended position. This ensures that the assembly can be used for a large range of heights and/or distance between the floor and the ground of platform.
The drive arrangement is arranged so that the trailing end of the ramp body is supported on the upper control sprocket/pulley when the ramp body reaches the extended position.
The links at each side of said trailing end is connected to the endless drive by a tee connector having a shaft which extends into a stabiliser rod positioned between the links at said trailing end.
The ramp assembly may include interrupt means for interrupting operation thereof when an obstacle is in the path between the retracted position and the extended position. Sensor means employed for this purpose can be infra red sensors, switch means on any part of the ramp body or load sensing means.
In order to manually retract the ramp body during power failure, means may be provided to uncouple the ramp body from the drive arrangement.
Travel limiting means may also be arranged so that the drive arrangement automatically stops at the retracted position and at the extended position.
The travailing speed of the ramp body is preferably variable so that the authority can select a suitable speed.